Method of and apparatus for reinforcing and supporting mine roofs and the like



June 29, 1954 J, BIERER METHOD OF AND APPARATUS FOR REINF'ORCING AND SUPPORTING MINE ROOFS AND THE LIKE Filed April 15, 1950 ATTORNEYS.

Patented `lune 29, 1954 METHOD F AND APPARATUS FIOR REIN- FORCING AND SUPPORTING MINE ROOFS AND THE LIKE Joseph Bierer, South Charleston, W. Va. Application April 15, 1950, Serial No. 156,199

Claims. 1

This invention relates, as indicated, to a method of and apparatus for reinforcing and supporting mine roofs and the like.

Although this invention is particularly adapted for reinforcing and supporting mine roofs, it is to be understood that its principles are adaptable for reinforcing and supporting the interior surface of any subterranean opening wherein there is a possibility of the material forming such interior surface collapsing and falling into the opening. In subterranean openings of the character referred to, the danger from cave-ins is well known. In such case, the material forming the surface of the opening or mine gives way and falls into the opening or mine thereby causing an obstruction and frequently injury to occupants therein. This invention is primarily concerned with the elimination of this defect or danger in mine openings and the like.

One of the principal objects of this invention is to provide a novel method of forming a reinforcement for the surface of a mine or other subterranean opening.

A further object of the invention is to provide an improved method of forming a reinforced concrete anchor in the surface of a subterranean opening.

Another object of the invention is to provide a metal-reinforced concrete anchor for a mine roof which is formed in an opening cut in the mine roof.

A still further object of the invention is to provide a reinforced concrete anchor for a mine roof which is formed in an opening cut in the mine roof.

A still further object of the invention is to provide a reinforced concrete anchor of the character referred to for mine roofs in which there is a reinforced concrete cap at the outer end of the anchor to provide a support for the mine roof about the outer end of the roof opening.

A still further object of the invention is to provide a. novel method of forming a reinforced concrete anchor and supporting cap of the character referred to.

Other objects and advantages of the invention will become apparent from the folowing description.

In the drawings, there is shown a preferred embodiment of the invention. In this showing:

Fig. 1 is a vertical sectional view of a reinforcing anchor and supporting cap constructed in accordance with the principles of this invention and illustrated in an operative position in an opening formed in the mine roof;

y modified form of reinforcing tube; and

Fig. 5 is a fragmentary sectional View diagrammatically illustrating a connection by Which concrete may be forced into the cap housing of Figs. 1 and 2.

Referring first to Figs. 1 and 2 of the drawings, the numeral I designates the material forming the roof surface of a mine or other subterranean opening. The roof I has an opening 2 drilled therein for the reception of the reinforcing and supporting structure of this invention. As illustrated, this reinforcing and supporting structure comprises a hollow metal tube 3 which is mounted concentrically in the opening 2. In the showings of Figs. 1 and 2, the tube 3 is cylindrical and is formed with a plurality of slots l in its upper end. It is mounted in position by moving it and an expanding wedge 5 axially upwardly through the opening 2 until the upper end of the wedge 5 strikes the end 6 of the opening 2. The lower Y end of the tube 3 extending from the opening 2 is then struck one or several blows with a hammer and the slotted upper end of the tube 2 is expanded by the wedge 5 and forced into tight holding engagement with the inner surface of the opening 2. The tube 3 has a diameter substantially smaller than the diameter of the opening 2 so as to provide an annular space 'I between the tube and the roof opening in which it is mounted. The wedge 5 has a diameter only slightly smaller than the diameter of the opening 2 so that it may be moved without interference to the inner end of the opening 2.

After the tube 3 is mounted in position as described above, a U-shaped reinforcing channel 8 is placed in position over its lower end, the channel being provided with an opening d through which the lower end of the tube 3 extends. A sheet metal housing I6 having an annular felt washer Il for sealing engagement with the surface I2 of the mine roof is then placed over the lower end of the tube. The housing It and reinforcing channel 8 are secured in position by a nut I3 which is threaded on the lower end of the tube 3. The nut I3 operates to clamp the housing II! and reinforcing channel 8 in position through the medium of a wedging member I4 having pointed tips for engagement in a slot I5 formed in a metal washer I6, there being a felt washer I'I between the metal washer I6 and the housing I0. The wedging member I4 and the metal washer I6 act as motion transmitting members, but function in such manner that only axial movement f the nut I3 is transmitted to the belt washer I'I and housing I8.

The housing Il] and its supporting structure provides a sealed container about a relatively large area at the lower end of the opening 2. The interior of the housing I0 and the annular space 'I about the tube 2 is thereafter filled with concrete grout in a manner to be described. The expression concrete is used herein in its generic sense and is intended to mean mortar or any other material which may be forced into the container I0 in a fluid-like condition, and which will thereafter set and adhere to the surface of the opening 2 and the metal reinforcement therein. For filling purposes, the housing Ulis provided with an opening I8 through which concrete grout may be forced, there being a closure member I9 for the opening I8 with a mounting (not shown) by which it maybe moved to and from a position closing the opening I8. 'Concrete grout is forced in the housing II] under pressure by a suitable pump (not shown) through a flexible connection 2B having a coupling 2l at its end for insertion in the opening I3 as best shown in Fig. 5. The concrete is forced into the housing IG under pressure until it fills the space within the housing and about the lower end of the tube `3, after which it will be forced upwardly through the annular space 'I.

Air in the annular space l, and water above the concrete moving upwardly through the space 'I may escape through the slots in the upper end of the tube 3. The hollow construction of the tube 3 and slots 4 provide a vent to prevent trapping of air and drainage water in the opening 2 so as to interfere with the upward movement of the concrete grout through the annular space 1. When the annular space 'I is completely lled with concrete, the fitting '2l is withdrawn from the opening IB, and the closure member l) is operated to a closedposition to prevent escape of the concrete.

As soon as the concrete filling has set, there is provided a reinforced concrete structure 22 functioning as an .anchor within the opening. The reinforced concrete anchor 22 comprises the metal tube 3 and the concrete cylinder'23 thereabout. The concrete cylinder 23 is to all intents and purposes an integral part of the formation in which the opening 2 is drilled. This is due to the fact that the concrete forced into the annular space 'I flows into the cracks between the various strata through which the drilled opening 2 extends, and into the crevices and irregularities on the surface of the opening 2 which were formed by the drilling operation. The concrete grout forced into the opening is prepared with a rather thin consistency, and will thus flow into all crevices and interstices along the surface of the opening 2. Consequently, when the concrete cylinder 23 has set, it will cling tenaciously to the sides of the opening 2 and will function to prevent separation of the strata along the opening 2 and to prevent the structure 22 from being pulled out of such opening. in addition, the tube 3 functions as a metal reinforcement for the interior of the concrete cylinder 23.

The reinforcing channel 8 and housing I- with the concrete therein form a supporting cap 24 at the lower end of the anchor 22. To all intents and purposes, the cap. 24 is a metal-reinforced concrete cap which is integrally and CTI rigidly connected to the lower end of the anchor 22. This cap is tightly engaged with the roof surface I2 in a relatively large area about the lower end of the opening 2 and thus constitutes a direct support for the roof material above the cap 24. The material above the cap 24 cannot move downwardly without imparting a similar movement to the cap 24, anddownward movement of the cap 24 is of course prevented by the anchor 22. The length of the anchor 22 and diameter of the cap 24 will be dependent upon the earth strata in which the subterranean opening is formed. It will also be understood that the opening 2 may be'formed at any angle relative to the surface I2 of' the subterranean opening other than the particular angle illustrated.

`Althougha `wedge 5 has been illustrated for expanding the upper end of the tube 3 to initially secure the tube 3 in position, the upper end of the tube 3 may be formed so as to eliminate the necessity of the expanding wedge 5. A modification for this purpose is illustrated in'Fig.' 3 wherein the upper end 30 of the tube 3 is provided with a plurality of diamond-shaped openings 3| so as to provide narrow connecting members 32 at spaced intervals around the tube 3. With this construction, a blow against the'lower end of the tube 3 will be effective to spring the parts `32 outwardly into holding engagement with the sides of the opening 2. In order' to make certain that the portions 32 of reduced dimensions will spring outwardly, an initial set'in an outward direction may be imparted to the parts 32 before the tube '3 is inserted in a roof opening 2.

Another modification for securing a hollow tube in position within an opening 2 is illustrated in Fig. 4. In this showing, an elongated bolt 40 having a attened upper end 4I is provided. The flattened upper end #I has a dimension greater than the diameter of the tube 3 so that its end 42 will be expanded into the sides of the opening 2 to secure the tube 3 in position when the tube 3 is moved upwardly relative to the bolt 4Q. This structure is rst secured in position by moving the bolt d0 endwise through the opening 2 until the end 4I strikes the end of the opening 2. The end 4I is then driven into the end 5 of an opening 2 to secure the bolt firmly in position. The tube 3 is then moved axially in an endwise direction over the bolt d until its end l2 engages the side of the wedge il at the end of the bolt 40. A nut 43 and washer 54 are then applied to the lower end of the tube and bolt so as to move the tube 3 upwardly over the bolt 4E) to expand its ends 42 into engagement with the earth strata in which the opening'2 is formed.

The modifications of both Figs. 3 and 4 provide structures for temporarily securing the tube v3 in position within an opening 2. In both modifications, there will be .provided an annular1 surface l about the tube 3 which maybe lled with concrete to provide a reinforced anchor in an opening 2, the tube venting the opening during the filling operation. The hollow formation of the tube 3 in both modifications enables grout to .be readily forced into the annular space 'I.

From theforegoing, it will be noted that .there is provided a novel form of roof support comprising the reinforced anchor 22 and thereinforced concrete cap 24. Attention is particularly invited to thefact that the roof support of this invention functions both as a support and as a reinforcement for the roof. The reinforced concrete anchor l22 .within the roof opening 2 functions to tie together the various strata of earth along the opening i2 in addition to forming a mounting structure for the supporting cap 251. Attention is also directed to the fact that reinforcing support of this invention is fabricated in a novel manner, the fabrication being completed in the position to be iinally occupied. rThe material reinforcing parts are iirst mounted in the relative positions which they are to occupy atfter the reinforcing supporting structure is completed. The completion of the reinforcing and supporting structure is then accomplished by forcing the concrete grout into the space provided therefor.- The concrete about the reinforcing metal additionally functions a protective covering for the metal parte against the corrosive action of the drainage water con monly encountered in subterranean openings.

While I have illustrated and described one specific embodiment of my invention, it will be understood that this is merely by way of illustration, and that various changes and modifications may be made therein within the contemplation of my invention and under the scope of the following claims.

I claim:

1. A mine roof reinforcing structure comprising a hollow rod inserted in a pre-formed opening in a mine roof, means at one end of the rod engaged with the roof at the inner end of the roof opening for expanding the upper end of the rod upon continued movement of the rod into the opening to provide an expanded connection in tight engagement with the roof securing the rod against movement out of the opening, sai-d rod having an outer surface spaced from the inner surface of said opening to provide a space between such surfaces extending lengthwise of the opening, and a filling of concrete in said space for binding together the roof strata through which said opening is formed, the rod forming a reinforcement for the concrete in said space, and a metal-reinforced concrete cap at the lower end of the roof opening engaged with the mine roof in an area about the lower end of said opening, said cap. being rigidly secured to the lower end of the anchoring rod in said opening.

2. A mine roof reinforcing structure comprising a hollow rod inserted in a pre-formed opening in a mine roof, means at one end of the rod engaged with the roof at the inner end of the roof opening for expanding the upper end of the rod upon continued movement of the rod into the opening to provide an expanded connection in tight engagement with the roof securing the rod against movement out of the opening, said rod having an outer surface spaced from the inner surface of said opening to provide a space between such surfaces extending lengthwise of the opening, and a filling of concrete in said space for binding together the roof strata through which said opening is formed, the rod forming a reinforcement for the concrete in said space, and a metal-reinforced conrete cap at the lower end or" the roof opening engaged with the mine roof in an area about the lower end of said opening, cap having a concrete body integral with the concrete in said opening, the metal reinforcement in said cap having a connection directly to said rod.

3. A mine roof reinforcing and supporting structure for cooperation with a drilled opening formed in a mine roof which comprises a hollow rod inserted in said opening and cooperating therewith to define an annular space about the inner surface of the opening, fastening means on said rod for securing it in position within said opening, a housing at the lower end of said rod dening an enclosure communicating with said annular space, a metal reinforcing device within said enclosure, and an opening in said housing through which concrete may be forced under pressure to fill said enclosure and annular space, the upper end of said rod having openings therein for venting said annular space and enclosure.

4. A reinforcing support for mine roofs having a drilled opening therein comprising a housing member about the mouth of said opening, a metal anchor extending inwardly into said opening and having a mounting connection with said housing at its outer end, said anchor being of a size smaller than said opening to provide a space thereabout, and a nlling of concrete in said housing and space to thereby provide a reinforced concrete supporting cap engaged with the mine roof about the mouth of said opening having a reinforced concrete mounting member anchoring it in said opening.

5. A method of reinforcing mine roofs which comprises positioning a hollow metal tube in a drilled opening in the mine roof to provide an annular space about the tube, mounting a housing on the end of said tube about the mouth of said roof opening, and then filling nrst said housing and thereafter said annular spacewith concrete while utilizing the tube as a vent to exhaust air from said annular space in advance of the concrete lling.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,883,196 Wertz Oct. 18, 1932 1,926,415 Wertz Sept. l2, 1933 FOREIGN PATENTS Number Country Date 91,457 Austria of 1923 46,278 Norway of 1929 

